Horizon discovers what your cat really gets up to when it leaves the cat flap. In a groundbreaking experiment, 50 cats from a village in Surrey are tagged with GPS collars and their every movement is recorded, day and night, as they hunt in our backyards and patrol the garden fences and hedgerows. Cats are fitted with specially developed cat-cams which reveal their unique view of our world. You may think you understand your pet, but their secret life is more surprising than we thought.

Bladderwort utricularia is a pond-dweller that is among the fastest known, its traps snapping shut in less than a millisecond. As the seasons change, David demonstrates how plants operate on a different time scale to us; how they modify their lives according to the time of year. We discover insects’ hidden links with plants, both as pests and pollinators. UV-sensitive 3D cameras reveal the invisible alter-ego of plants and their flowers’ mesmerizing patterns; a parallel-dimension of strange colours and stunning patterns through which plants communicate with them. With the aid of visual effects, David steps among the swirling vortices of plant scent; communication signals with which plants are inextricably plugged in to the natural world. And using a tuning fork, he demonstrates how plants and insects can even communicate with music. As autumn envelopes the Gardens, fungi reveal themselves not as the enemies of plants but their vital allies. In Kew’s atmospheric Fungarium, David discovers a specimen that has the power of mind control and another that lives underground where it has grown to be so big it can be counted as the largest single organism on the planet. It is 6 times bigger than Kew Gardens itself.

Can we find the Garden of Eden? Bible scholar Dr Francesca Stavrakopoulou thinks so. In the final episode of her series re-examining conventional readings of the Bible, she argues that the Garden of Eden has nothing to do with the origins of humanity, but is rather a story concealing dramatic events about a particular figure in a particular place, two and half thousand years ago. Marshalling compelling evidence from archaeology, Islam and the Bible text itself, she identifies and visits the exact site of Eden. It's a revolutionary theory which challenges some of the most cherished preconceptions about Eden in both Christianity and western culture.

Grasslands feed the world. Over thousands of years, we humans have learned to grow grains on the grasslands and domesticate the creatures that live there. Our success has propelled our population to almost seven billion people. But this episode reveals that, even today, life in the 'Garden of Eden' isn't always rosy. We walk with the Dorobo people of Kenya as they bravely attempt to scare off a pride of hungry lions from their freshly caught kill. We gallop across the Steppe with extraordinary Mongolian horsemen who were 'born in the saddle'. And in a perfect partnership with nature built up over generations Maasai children must literally talk to the birds! The honeyguide leads them to find sweet treats, but they'll have to repay the favour.

Open your eyes to the bizarre, ferocious and surprisingly beautiful world of the invertebrates, a ground-breaking exploration into a spectacular miniature universe never normally seen but teeming all around us. In the first episode, the story of the land-living invertebrates. Discover the private life of Europe's dramatic leopard slug, a common garden resident with a truly bizarre end to its marathon mating ritual; watches the courtship ballet of tiny springtails on the underside of a leaf; sees swarms of bright red South African millipedes find partners, and in the caves of Venezuela meets the giant bat-eating centipede.

As the early June sun begins to set over a calm river in Central Hungary, masses of ghostly shapes emerge from their larval cases to take to the air for the first time. They are mayflies and in a spectacular display, thousands of them demonstrate how the very first wings were used. From the stunning aerobatics of hoverflies in an English garden to the mass migration of purple crow butterflies in the valleys of Taiwan, this episode tells the tale of the first animals ever to take to the air. Unique footage reveals the lightning fast reactions of bluebottles and hoverflies, filmed with one of the world's fastest cameras, and Sir David Attenborough handles the world's largest (and perhaps most ferocious) insect - the Titan beetle.